#1  
Old 05-02-2019, 09:20 PM
gaseous's Avatar
gaseous (Patrick)
Registered User

gaseous is offline
 
Join Date: May 2016
Location: Brisbane
Posts: 782
Star formation question

Possibly a silly question that hopefully some of the smart folks on here can answer. If a protostar/brown dwarf gains enough mass to initiate nuclear fusion in its core and become a star, how long does it take for the “starness” to become apparent? Given that it can take 100,000 years for a newly-minted photon to travel from the core of a star to the surface, would that then imply that a star might take 100,000 years to visibly “switch on” after nuclear fusion has commenced?
Reply With Quote
  #2  
Old 06-02-2019, 04:56 PM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,551
Hi Patrick

I'm not an expert, but from what I remember Brown dwarfs are the same size as Jupiter but have more mass and generate more heat than what Jupiter does and they are visible in Infrared only. For the dwarf to start the fusion of Hydrogen its diameter would have to increase at least 10 times or more, in which case it would no longer be called a brown dwarf.

As for the 100,000 years for light to pass through the star, I believe that figure is for our Sun, so it would vary depending on the final diameter of the Star.

Cheers
Bill
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 10:35 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement